Graham Stapleton, Chief Commercial Officer at Carphone Warehouse, told the Daily Telegraph that it was good to see the tablet market diversify.

"It's impressive that this product is our biggest selling Android tablet, and it will be really interesting to see if other manufacturers will follow suit with smaller tablets over the coming months to spice up the Christmas period," he said.

However while the Nexus 7 currently enjoys the lead among seven-inch devices, it may not have lond to enjoy the title.

Apple is widely expected to unveil its own seven-inch device as soon as next week. Known unofficially as the iPad Mini, the device would be anticipated to sell millions of units in its first week of sale if priced to match the Nexus 7 and Kindle Fire HD.